The present invention relates to lamps, and more specifically to such lamps used on the rear of vehicles.
Rear lamps on vehicles are governed by regulations, in the U.S. and other countries. These include, for example in the U.S.A., 49 C.F.R. Sec. 571. These may generally include one or more requirements regarding candela, illuminated surface area, placement, and other attributes, normally grouped by various function or location. The Federal Motor Vehicle Safety Standard, FMVSS 108, in Part 571.108 of the Code of Federal Regulation Title 49, specify that vehicles over 2032 mm wide are required to have stop lamp with a lens area (Effective Projected Luminous Lens Area (EPLLA)) of at least 75 square centimeters. Other vehicles EPLLA requirements vary. The area for cars need be at least 59 square centimeters. A circular stop lamp used on a large trailer today will be approximately 10 cm in diameter or about 78.5 square cm of area. This may be met, for example, with a standard nominal 4 inch or 10 cm diameter circular lamp, meaning the housing is also circular and has a diameter of about ten (10) centimeters (or about 4 to 4½ inches), or with an oval shaped lamp, meaning that the housing is also oval. The size and shape of such oval housing may vary, but a typical example may be an oval with dimensions of about 2½ inches tall and about 6¾ inches wide. As shown here it is desirable to meet illuminated surface area requirements or goals while providing an arrangement that is more space efficient. Various stop-tail-turn (STT) lamps used LEDs with a large lamp with separate cavities or other areas, such as one cavity for the STT functions and another for other functions, such as a dedicated white LED backup light. Other LED STT lamps use additive chromatic effects to alter color patterns. Also, separate dedicated lamps, such as separate white LED back-up (or reverse) lamps, have been used. While each approach has various pros and cons, they do not provide the arrangements and advantages of the present claimed designs.
Thus, there is a need for improvement in this field.